THE HAGUE, Netherlands – Prosecutors at the war crimes trial of Slobodan Milosevic (search) may have produced the first document linking the former Yugoslav president to the massacre of thousands of Bosnian Muslims inSrebrenica (search), legal experts said Friday.

The killing of 7,500 Muslims at the U.N. protected enclave of Srebrenica in July 1995 was the worst massacre in Europe since World War II.

Milosevic faces 66 counts of war crimes, including genocide for Srebrenica. He has denied knowledge or involvement in the killings. He has been on trial since February 2002 and is defending himself despite serious heart trouble and illness that has repeatedly delayed hearings.

The one-page document, introduced last week, is dated July 10, 1995, two days before the killings started at the end of the 1992-1995 Bosnian war.

The document is signed by theBosnian Serb (search) wartime staff commander and chief of police, Tomislav Kovac, and written on Bosnian Serb Interior Ministry letterhead.

It orders seven subordinate officers to move their troops, including the Serbian police unit, to "crush the enemy" in Srebrenica. Milosevic was president of neighboring Serbia at the time.

"It is very significant, it is the first piece of evidence that places Serbian police in Srebrenica," said Judith Armatta, of the Coalition for International Justice, a Washington-based advocacy group. "But whether these troops were involved in the massacres is yet to be seen."

Prosecution spokeswoman Florence Hartmann said the document was just one element in the overall case against Milosevic. "We will have further elements and bring specific witnesses for Srebrenica," she said.

To gain a conviction, prosecutors must substantiate claims that Milosevic ordered or knew about the Srebrenica atrocities, or compelled the Bosnian Serb leaders to carry them out.

"It is without a doubt the first document indicating forces from Serbia participated in the fighting," said Mirko Klarin, head of the Brussels-based Croatian news agency SENSE that reports on the tribunal. "But in itself, this document is not enough, it is not the smoking gun."

Former Yugoslav President Zoran Lilic testified earlier this week that he believed Milosevic could not have ordered the Srebrenica massacres.

Bosnian Serb wartime leaders, Radovan Karadzic and Gen. Ratko Mladic, have also been charged with genocide for Srebrenica, but remain at large.